1. Field of the Invention
This present invention relates to a reflective phase retarder and a semiconductor light-emitting device including such reflective phase retarder.
2. Description of the Prior Art
The wave plate, also named as phase retarder, is used to convert polarization of light beams. Most of prior arts phase retarders are transmissive type which is applicable in optical systems to convert polarization of transmissive light beam.
Reflective phase retarders have been applied in some optical systems, such as micro-projectors, to satisfy need of high contrast ratio for micro-projection by enhancing polarization efficiency of backlight modules in the micro-projectors.
With respect to prior arts of reflective phase retarders, periodically arranged metal protruding strings and grooves to constitute metal diffraction grating are provided, with drawback of being difficult to manufacture. Alternately metal particles are used to constitute a rough surface as a reflective phase retarder, but it is only successful in laboratory since its difficulty to practice.
In addition, semiconductor light-emitting devices using reflective phase retarders have not been devised yet.